Portion of a carton



FIG. 1 is a front perspective view of a portion of a carton of the present invention shown in a position of use as part of a carton structure drawn in broken line;

FIG. 2 is a plan view of the outer surface of the portion of a carton of FIG. 1 shown in a position of use as part of a carton structure drawn in broken line; and,

FIG. 3 is a rear perspective view of the carton structure of drawn broken line of FIG. 1 included to show the portion of a carton in a position of use.

The broken line structure and the areas within the broken lines are included for the purpose of showing the design in a condition of use and form no part of the claimed design. 

The ornamental design for a portion of a carton, as shown and described. 